BEVERLY HILLS, Calif. — The vibe was mellow, the feeling warm and the spirit willing as Cee Lo Green, Christina Aguilera and Adam Levine hugged it out in a weekend reunion of three of the four original coach-mentors on The Voice.

Television’s most absorbing, unpredictable singing competition doesn’t return with a new season until September, but the three seemingly incompatible singing artists — frontman of the pop-rock band Maroon 5, a Latin-influenced soul diva and a hip-hop rap-and-soul artist — were determined to renew old acquaintances, even if the absence of Blake Shelton, mentor of the past season’s Voice winner, 16-year-old country newcomer Danielle Bradbery, was keenly felt.

Some have dismissed The Voice for not producing a bona fide music star in its four seasons to date, but there are signs Bradbery may be about to change that. This past week, the small-town Texas high-school junior, who reportedly never performed before a big crowd before her mother talked into auditioning for The Voice, posted her highest debut so far on Billboard’s Hot Country Songs chart.

Bradbery’s radio-promoted single The Heart of Dixie debuted at No. 16 on the Country Songs, according to Nielsen Soundscan, with 78,000 downloads and climbing — not bad for a young, up-and-coming performer who won’t graduate from high school until 2015, and who had never taken a single vocal lesson until Shelton and his country-artist wife Miranda Lambert took Bradbery under their wing.

Danielle Bradbery, left, Zach Swon, Blake Shelton and Colton Swon of The Swon Bros, on The Voice’s Live Finale show.

Shelton, the Country Music Association’s 2012 Entertainer and Male Vocalist of the Year, picked Bradbery out-of-the-blue, judging her on her voice alone, during The Voice’s blind audition phase. The Voice is unique in that singers perform on stage with the judges’ backs turned to them. The show’s judges choose who to mentor based on hearing the voice, and the voice alone.

Shelton’s picks have gone on to win three of The Voice’s four seasons so far.

“I understand I’m coming back to the ‘Blake Shelton Show’ at this point,” Aguilera said wryly.

Levine returns for his fifth season as a coach-mentor this fall. Aguilera and Green will return to The Voice after a single season’s absence, to accommodate performing tours. Their replacements Shakira and Usher will return for The Voice’s sixth season, in 2014.

The Voice’s rotating panel of judges has proven surprisingly stable, even as the judging panels on rival music programs American Idol and The X Factor have been wracked with turmoil.

Aguilera insisted the competition with Shelton is friendly, and that the frequent jabs and barbs are in jest.

The Voice’s personable vibe has elevated it above the unseemly bickering that has become a signature of other TV talent competitions, and viewers have responded accordingly. The Voice has seen its ratings steadily climb, even as the other programs’ numbers have faded.

“I think we all agree that it’s the contestants that win at the end of the day and not us,” Aguilera said.

“Obviously, winning is the end goal when you’re on The Voice,” Levine said. “For me, though, it’s amazing to just work with these people and help them get to wherever they’re going. At whatever point in the competition they go home, they’ll go home with all these amazing experiences, based on things we’ve experienced in our own careers and handed down to them.

Adam Levine

“Winning is great — don’t get me wrong. I hate it that Blake has won three in a row. But winning isn’t always the point. As long as we do our jobs and teach these singers what we know and be honest about it and help them along, we win. We’ve been very lucky in our careers. It’s a fun show to be a part of. I don’t think any of us really cares, deep down, if we ‘win’ or ‘lose.’ I think it’s more about preparing the people on our teams for what’s ahead of them, and have a great experience while doing it.”

Some of The Voice’s most vocal fans are in front of the camera, on the judges’ panel, and not just watching from home, Levine added.

“We love this show. We’re huge fans of this show. All of us. We wouldn’t do it if we weren’t.”

Levine said he’s not losing sleep over the fact that The Voice has yet to break a top-selling star.

“It would be nice if we were to launch a huge star,” Levine said. “A lot of things have to fall into place for that to happen, though. The goal of the show is to do what we can for these amazing singers while they’re on the show, to get somebody out in front so they can win. We all know that the lightning-in-a-bottle you need to capture to be successful in this business is extraordinarily difficult.

“It would be really amazing if that happened. The fact that it hasn’t happened yet doesn’t seem like a shortcoming of the show. It just seems like something that hasn’t happened yet.”